1. Field of the Invention
The invention relates to a mobile communication network system, a method of operation, and a mobile station in such a system according to the preamble of the independent claims. In particular, the invention relates to direct communication and localisation of mobile end equipment and emergency handling.
2. Description of the Related Art
U.S. Pat. No. 6,047,178 discloses a way of direct communication between two mobile stations using a voice channel, under the supervision of mobile network MSC.
This patent application (Ser. No. 10/110,238) in comparison provides a communication from one mobile station to others as through broadcast messages using repeated broadcast messages as SOS messages and without supervision of mobile network. It is operable even when there is no network available.
Patent Application Publication US 2002/0086659 shows a way of handling emergency messages efficiently in that the messages are directed to a device (away from the SOS sender and a device as part of the network itself, for example an MSC), which has a database, in that it recognises the type of message and knows other mobile devices in the vicinity so that the emergency message can be directed towards these mobile devices.
This patent application (Ser. No. 10/110,238) in comparison discloses an emergency system in that the mobile phone sends emergency messages as periodically repeated (SOS) messages, which are directly detected by the authorized mobile devices in the vicinity. These devices have means to dynamically locate the position of the SOS sender. This is achieved with a high precision of localization, due to repetition of the messages that convey information to help positioning.
U.S. Pat. No. 4,534,061 discloses deterministic multi-access method for a decentralized mobile radio system. A mobile radio system uses a predetermined number of control channels over which a hand-shake routine is performed to determine called station availability, before one of a limited number of talk channels (local and repeater) is assigned for communication between a calling and the called station.
This patent application (Ser. No. 10/110,238) in comparison allows a mobile station to use a pre-allocated broadcast channel, to broadcast weak emergency messages, as to be detected by other mobiles in the near vicinity.
U.S. Pat. No. 5,901,342 relates to a method of establishing a call between two mobile stations.
This patent application (Ser. No. 10/110,28) in comparison relates to sending direct messages from one mobile to others without direct intervention of the mobile network.
U.S. Pat. No. 5,890,054 discloses a routing protocol, which enables emergency communication between a distressed mobile device and the system backbone, using another mobile device as intermediary.
Within this patent application (Ser. No. 10/110,28) in comparison, a method is described where another mobile device take over the SOS message sending, in case the distressed mobile telephone runs out of battery. In which case however, it does not convey the emergency message to a certain address but instead start broadcasting the original message the same way as the SOS phone.